The present invention relates generally to medical devices and more particularly to intraluminal balloon catheters.
Balloon catheters are widely used in the medical profession for various intraluminal procedures. One common procedure involving the use of a balloon catheter relates to angioplasty dilation of coronary and other arteries suffering from stenosis (i.e., a narrowing of the arterial lumen that restricts blood flow). Angioplasty procedures have become a popular alternative to traditional procedures for treating stenoses because angioplasty procedures are considerably less invasive than other alternatives. For example, stenosis of the coronary arteries has traditionally been treated by performing bypass surgery. In general, bypass surgery involves splitting the chest bone to open the chest cavity and grafting a replacement vessel onto the heart to bypass the blocked, or stenosed, artery. However, coronary bypass surgery is a very invasive procedure that is risky and requires a long recovery time for the patient. Angioplasty procedures are also useful for treating stenoses in other regions of the vasculature as well, such as the carotid, brachial, renal, iliac and femoral arteries. In addition, angioplasty may be used to treat other vessels and passageways in the body.
Typically, angioplasty procedures are performed using a balloon-tipped catheter that may or may not have a balloon-expandable stent mounted on the balloon. In general, a physician performs an angioplasty procedure by introducing a balloon catheter into a peripheral artery (commonly one of the leg or arm arteries) and threading the catheter to the narrowed region of the artery. During this stage, the balloon is uninflated and collapsed onto the shaft of the catheter in order to present a low profile which may be passed through the arterial lumens. Once the balloon is positioned at the narrowed region of the artery, the balloon is expanded by pumping a mixture of saline and contrast solution through the catheter to the balloon. As a result, the balloon presses against the inner wall of the artery to dilate it. If a balloon-expandable stent is mounted on the balloon, the balloon inflation also serves to expand the stent and implant it in the artery. After the artery is dilated, the balloon is deflated so that it once again collapses onto the shaft of the catheter. The balloon-tipped catheter is then retracted from the arteries. If a stent is mounted on the balloon of the catheter, the stent is left permanently implanted in its expanded state at the desired location in the artery to provide a support structure that prevents the artery from collapsing back to its pre-dilated condition. Alternatively, the balloon catheter may be used to dilate a stenosis without implanting a stent. A balloon-expandable stent or self-expandable stent may then be implanted in the dilated region in a follow-up procedure. If desired, a physician may also dilate the artery and stent a second time after the stent is implanted with a balloon catheter.
Although treatment of stenosed arteries in the vasculature is one common example where balloon catheters are used, this is only one example of how balloon catheters may be used and many other uses are possible. For example, balloon catheters may also be used to temporarily occlude vessels during medical procedures to prevent blood or other fluids from flowing through a vessel. Balloon catheters may also be used to expand other intraluminal devices without dilating the surrounding vessel wall, such as stent-grafts that may be used to treat aneurysms.
The above-described examples are only some of the applications in which balloon catheters are used by physicians. Many other applications for balloon catheters are known and/or may be developed in the future.